docs: enhance README with key features and add flight info extraction example

[pierrevalade]

This PR enhances the project documentation and adds a new example:

Key Changes:

1. README Improvements:

   • Added comprehensive list of key features (model-agnostic, observability, cost tracking, etc.)
   • Included a practical example of a flight information extraction agent
   • Added links to documentation and web application
   • Improved overall formatting and organization

2. New Example:

   • Added examples/18_flight_info_extraction.py demonstrating structured data extraction
   • Shows how to use Pydantic models for type-safe output
   • Includes a realistic email parsing scenario
   • Added corresponding playground screenshot

The changes make the project more approachable for new users while showcasing its key capabilities through practical examples.

[Copilot]

Pull Request Overview

This PR enhances project documentation by updating the README with key feature highlights and by adding a new example demonstrating flight information extraction using Pydantic and the WorkflowAI SDK.

• Updated README with detailed key features and an embedded, runnable flight info extraction example.
• Added a new example file (examples/18_flight_info_extraction.py) showcasing how to build an agent for parsing flight details from emails.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
examples/18_flight_info_extraction.py	New example demonstrating flight info extraction using Pydantic and WorkflowAI.
README.md	Enhanced documentation with key features, an embedded example, and a screenshot.

[pierrevalade]

@guillaq ready for review, thanks!

[guillaq]

🚀 🚀 🚀 🚀

[pierrevalade]

@guillaq ready for review again, thanks.